This invention relates to certain herbicidal thiadiazoloazines, agriculturally suitable compositions thereof and a method for their use as a general or selective preemergent or postemergent herbicide or as a plant growth regulant.
New compounds effective for controlling the growth of undesired vegetation are in constant demand. In the most common situation, such compounds are sought to selectively control the growth of weeds in useful crops such as cotton, rice, corn, wheat and soybeans, to name a few. Unchecked weed growth in such crops can cause significant losses, reducing profit to the farmer and increasing costs to the consumer. In other situations, herbicides are desired which will control all plant growth. Examples of areas in which complete control of all vegetation is desired are areas around railroad tracks, storage tanks and industrial storage areas. There are many products commercially available for these purposes, but the search continues for products which are most effective, less costly and environmentally safe.
U.S. Pat. No. 4,872,901 discloses herbicidal thiadiazoloazines of the formula ##STR1## wherein R.sub.1 is a pyrazolyl group which may be substituted;
R.sub.2 and R.sub.3 are respectively lower alkyl or lower alkoxy; and PA1 Z is CH or N. PA1 R.sub.2 and R.sub.3 are independently lower alkyl or lower alkoxy; PA1 Z is CH or N; and PA1 n is 0 or 1. PA1 Y is H, halogen, alkyl or haloalkyl; PA1 R.sub.1 and R.sub.2 are independently alkyl, alkoxy or Cl; and PA1 Z is CH or N. PA1 Z is CH or N; and PA1 X and Y are independently halogen, lower alkyl or lower alkoxy. PA1 Z is CH or N; PA1 1) when X and/or Y is C.sub.1 haloalkoxy, then Z is CH; and PA1 2) when L is L-1 or L-2, then at least one of X and Y is NHCH.sub.3 or N(CH.sub.3).sub.2. PA1 1. Compounds of Formula I where if one of X or Y is NHCH.sub.3 or N(CH.sub.3).sub.2, then the other of X and Y is other than NHCH.sub.3 or N(CH.sub.3).sub.2. PA1 2. Compounds of Preferred 1 where X and Y are independently C.sub.1- C.sub.2 alkyl, C.sub.1- C.sub.2 alkoxy, OCF.sub.2 H or OCH.sub.2 CF.sub.3, or one of X and Y can be NHCH.sub.3 or N(CH.sub.3).sub.2. PA1 3. Compounds of Preferred 2 where Z is N. PA1 4. Compounds of Preferred 2 where Z is CH. PA1 5. Compounds of Preferred 4 where X and Y are independently CH.sub.3 or OCH.sub.3. PA1 N-(5,7-dimethoxy-2H-[1,2,4]thiadiazolo[2,3-a]pyrimidin-2-ylidene)-3-(ethyls ulfonyl)-2-pyridinesulfonamide (Formula I, L is L-4, X and Y are OCH.sub.3, and Z is CH) PA1 N-(5,7-dimethoxy-2H-[1,2,4]thiadiazolo[2,3-a]pyrimidin-2-ylidene)-1-methyl- 4-(2-methyl-2H-tetrazol-5-yl)-1H-pyrazole -5-sulfonamide (Formula I, L is L-6, X and Y are OCH.sub.3, and Z is CH)
EP-A-239,064 discloses herbicidal thiadiazoloazines of the formula ##STR2## wherein R is optionally substituted phenyl;
Japanese Patent Application 62[1987]-287088 and Japanese Patent Application 63[1988]-2080 disclose herbicidal thiadiazoloazines of the formula ##STR3## wherein X is H, halogen, alkyl, haloalkyl, alkoxy, haloalkoxy, alkoxyalkyl, haloalkoxyalkyl, C(O)N(R.sub.3)R.sub.4, C(O)OR.sub.5;
Japanese Patent Application 63[1988]-65049 discloses herbicidal bisdifluoromethoxy thiadiazoloazines of the formula ##STR4## wherein R is alkyl.
Japanese Patent Application 61[1986]-104,532 discloses herbicidal thiadiazoloazines of the formula ##STR5## wherein A is lower alkyl, lower alkoxycarbonyl, phenyl with or without a halogen substituent, 5- or 6-membered aromatic heterocyclic ring containing an oxygen, sulfur and/or nitrogen atom, aralkyl group;